It is well known in the art to prepare polyketones by Friedel-Crafts polymerization conditions. For example, U.S. Pat. Nos. 3,065,205; 3,516,966 and 3,441,538 describe the preparation of aromatic polyketones by Friedel-Crafts polymerization techniques utilizing typical Friedel-Crafts catalysts such as aluminum chloride, antimony pentachloride, ferric chloride, aluminum bromide, ferric bromide, etc. However, aromatic polyketones produced by such a process have been found to contain significant amounts of residual metal from the catalyst. This is a particular problem when aluminum chloride is used as the catalyst. Aluminum is different to remove since it is held tightly to the polymer as a complex with the carbonyl group in the polymer. The residual metal leads to thermal instability of the polymer at the high temperatures which are needed in order to fabricate the polymer.